The Confirmatory Bias Diet
By Arnold Kling
Seth Roberts, a psychologist at UC Berkeley has written a book called The Shangri-La Diet. In it, Roberts described some old obesity rat data and via “self-experimentation” developed a technique for weight loss that he hopes will change millions of lives.
…However, the scientific method exists for a reason: to root out poor hypotheses and to direct research towards those more likely to be fruitful. If Roberts were truly interested in investigating his approach, he should have subjected it to the dispassionate rigor of clinical study and peer review.
I was foolish enough to buy the book and try the diet. It was a total failure. It did not work for fellow TCS writer Glenn Reynolds, either.
In fact, if you think about it, the last thing you should believe in is a diet that was found to be successful primarily by the inventor of the diet. Dieting means reducing calorie intake, and the question is how you can motivate yourself to do that in a sustained way. If you are convinced that a diet will work, that may motivate you to stick to it. Having invented the diet yourself, you may be more convinced that it will work, and you will stick to it more easily. This is a form of confirmatory bias.
So let me propound the confirmatory bias diet. It works like this:
1. Invent any diet, as long as it leads you to reduce your calorie intake by, say, 150-200 calories a day.
2. Convince yourself that this is a brilliant new diet.
3. Try the diet on yourself.
Because of confirmatory bias–the desire to seek evidence that confirms your prior beliefs, you will have success with the diet.
Do I have the next diet book?